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701.
Anupam Agrawal Youngsoo Kim H. Dharma Kwon Suresh Muthulingam 《Production and Operations Management》2016,25(4):736-750
We investigate the optimal strategies for firms to invest in their suppliers when the benefits of such investments can spillover to other firms who also source from the same suppliers. We consider two Bayesian firms that can invest in improving the quality of their shared supplier; the firms do not have complete information on the true quality of the supplier, but they update their beliefs based on the supplier's performance. We formulate the problem as an investment game and obtain Markov perfect equilibria characterized by the investment thresholds of both firms. The equilibrium investment strategies of the two firms are characterized by a region of preemption and a region of war of attrition. We also examine how the interplay between spillover, competition, and returns from the investment at shared suppliers affect the investment threshold and the time to the leader's investment, and identify the conditions under which competition delays or hastens the first investment in a shared supplier. 相似文献
702.
Anne Hillairet de Boisferon Eve Dupierrix Paul C. Quinn Hélène Lœvenbruck David J. Lewkowicz Kang Lee Olivier Pascalis 《Infancy》2015,20(6):661-674
One of the most salient social categories conveyed by human faces and voices is gender. We investigated the developmental emergence of the ability to perceive the coherence of auditory and visual attributes of gender in 6‐ and 9‐month‐old infants. Infants viewed two side‐by‐side video clips of a man and a woman singing a nursery rhyme and heard a synchronous male or female sound track. Results showed that 6‐month‐old infants did not match the audible and visible attributes of gender, and 9‐month‐old infants matched only female faces and voices. These findings indicate that the ability to perceive the multisensory coherence of gender emerges relatively late in infancy and that it reflects the greater experience that most infants have with female faces and voices. 相似文献
703.
Self‐conscious Shyness: Growth during Toddlerhood,Strong Role of Genetics,and No Prediction from Fearful Shyness
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Natalie D. Eggum‐Wilkens Kathryn Lemery‐Chalfant Nazan Aksan H. Hill Goldsmith 《Infancy》2015,20(2):160-188
Fearful and self‐conscious subtypes of shyness have received little attention in the empirical literature. Study aims included the following: (1) determining whether fearful shyness predicted self‐conscious shyness, (2) describing development of self‐conscious shyness, and (3) examining genetic and environmental contributions to fearful and self‐conscious shyness. Observed self‐conscious shyness was examined at 19, 22, 25, and 28 months in same‐sex twins (MZ = 102, DZ = 111, missing zygosity = 3 pairs). Self‐conscious shyness increased across toddlerhood, but onset was earlier than predicted by theory. Fearful shyness (observed [6 and 12 months] and parents’ reports [12 and 22 months]) was not predictive of self‐conscious shyness. Independent genetic factors made strong contributions to parent‐reported (but not observed) fearful shyness (additive genetic influence = .69 and .72 at 12 and 22 months, respectively) and self‐conscious shyness (additive genetic influence = .90 for the growth model intercept). Results encourage future investigation of patterns of change and inter‐relations in shyness subtypes. 相似文献
704.
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706.
Claude‐Hélène Mayer Rian Viviers 《Australian and New Zealand Journal of Family Therapy》2015,36(2):289-306
Constellation work is a therapeutic and counselling intervention recognised in Germany and other European countries since the 1970s. Various scientists and practitioners have contributed to its theoretical and practical development, and research on the subject has increased over the past few years. However culture in constellation work has received little research attention and has not been empirically studied in African contexts. The aim of this article is to reflect on culture and its influence on constellation work in multicultural, post‐apartheid South Africa. An empirical qualitative research approach within the phenomenological paradigm was adopted. Six constellation facilitators were interviewed with in‐depth and field notes taken during participative observations of constellation workshops. The findings provide insight into culture in constellation work in the South African context. Theoretical and practical recommendations for scientists and therapy practitioners working with systemic interventions like constellation work are provided. 相似文献
707.
708.
Expanding Boundaries of Whiteness? A Look at the Marital Patterns of Part‐White Multiracial Groups
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Michael H. Miyawaki 《Sociological Forum》2015,30(4):995-1016
Using a boundary perspective (Alba and Nee 2003 ), I examine the marital behavior of three self‐identified multiracial groups: black/whites, American Indian/whites, Asian/whites. With a focus on marriage with whites, I assess whether the boundaries of whiteness are expanding to include these part‐white multiracial groups. Marrying whites at a large scale may signify that part‐white multiracial Americans are in the process of being accepted as “white.” At the same time, due to differences in the racial identity experiences of multiracial groups, marital patterns may differ by racial combination. Based on analysis of 2008–2012 American Community Survey data, I find that the majority of all three groups are married to whites, suggesting that most members in these groups are on the path to whiteness. On the other hand, multinomial logistic regression analysis demonstrates that American Indian/whites and Asian/whites are more likely than black/whites to have a white spouse, relative to spouses of another race/ethnicity. Moreover, separate regression analyses by multiracial group reveal gender differences in their likelihood of marrying whites for black/whites and Asian/whites. These results indicate racial stratification in the marriage market among part‐white multiracial Americans, with further stratification by gender for some groups. 相似文献
709.
Diesel Engine Exhaust and Lung Cancer Mortality: Time‐Related Factors in Exposure and Risk
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Suresh H. Moolgavkar Ellen T. Chang Georg Luebeck Edmund C. Lau Heather N. Watson Kenny S. Crump Paolo Boffetta Roger McClellan 《Risk analysis》2015,35(4):663-675
To develop a quantitative exposure‐response relationship between concentrations and durations of inhaled diesel engine exhaust (DEE) and increases in lung cancer risks, we examined the role of temporal factors in modifying the estimated effects of exposure to DEE on lung cancer mortality and characterized risk by mine type in the Diesel Exhaust in Miners Study (DEMS) cohort, which followed 12,315 workers through December 1997. We analyzed the data using parametric functions based on concepts of multistage carcinogenesis to directly estimate the hazard functions associated with estimated exposure to a surrogate marker of DEE, respirable elemental carbon (REC). The REC‐associated risk of lung cancer mortality in DEMS is driven by increased risk in only one of four mine types (limestone), with statistically significant heterogeneity by mine type and no significant exposure‐response relationship after removal of the limestone mine workers. Temporal factors, such as duration of exposure, play an important role in determining the risk of lung cancer mortality following exposure to REC, and the relative risk declines after exposure to REC stops. There is evidence of effect modification of risk by attained age. The modifying impact of temporal factors and effect modification by age should be addressed in any quantitative risk assessment (QRA) of DEE. Until there is a better understanding of why the risk appears to be confined to a single mine type, data from DEMS cannot reliably be used for QRA. 相似文献
710.
Reanalysis of the DEMS Nested Case‐Control Study of Lung Cancer and Diesel Exhaust: Suitability for Quantitative Risk Assessment
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Kenny S. Crump Cynthia Van Landingham Suresh H. Moolgavkar Roger McClellan 《Risk analysis》2015,35(4):676-700
The International Agency for Research on Cancer (IARC) in 2012 upgraded its hazard characterization of diesel engine exhaust (DEE) to “carcinogenic to humans.” The Diesel Exhaust in Miners Study (DEMS) cohort and nested case‐control studies of lung cancer mortality in eight U.S. nonmetal mines were influential in IARC's determination. We conducted a reanalysis of the DEMS case‐control data to evaluate its suitability for quantitative risk assessment (QRA). Our reanalysis used conditional logistic regression and adjusted for cigarette smoking in a manner similar to the original DEMS analysis. However, we included additional estimates of DEE exposure and adjustment for radon exposure. In addition to applying three DEE exposure estimates developed by DEMS, we applied six alternative estimates. Without adjusting for radon, our results were similar to those in the original DEMS analysis: all but one of the nine DEE exposure estimates showed evidence of an association between DEE exposure and lung cancer mortality, with trend slopes differing only by about a factor of two. When exposure to radon was adjusted, the evidence for a DEE effect was greatly diminished, but was still present in some analyses that utilized the three original DEMS DEE exposure estimates. A DEE effect was not observed when the six alternative DEE exposure estimates were utilized and radon was adjusted. No consistent evidence of a DEE effect was found among miners who worked only underground. This article highlights some issues that should be addressed in any use of the DEMS data in developing a QRA for DEE. 相似文献